Shock-limiting interface, compact (SLIC)

Abstract

A passive/reactive device protects a Payload from injury or damage due to the shock caused by impact or explosion. When the vehicle or structure mounting the Payload receives a shock pulse, the invention limits the acceleration transmitted from the vehicle or structure to the Payload to an acceptably low, user-adjustable level which is substantially constant or is some other user-adjustable force-displacement function. The invention is capable of doing so even when the peak magnitude of the imposed shock is on the order of thousands of G's, with a rise time to peak on the order of microseconds. The invention can be embodied to operate passively, without any external source of power, sensor system, or CPU, although they can be added to improve certain usability features. The invention also absorbs or dissipates the shock energy in substantially the minimum distance possible without exceeding the user-defined acceleration limit on the Payload. The invention can also react when a shock-producing impact is imminent by repositioning the Payload away from the impact site. The Payload can be a person or persons, or shock-vulnerable equipment. The shock can be created in a number of ways, including an explosion, an impact or collision, the slamming on high-performance boats and some off-road vehicles, earthquake, or even intentional shocks on an amusement thrill ride. The ability of the invention to protect against shock is limited only by its ability to absorb or dissipate the energy of the shock pulse on the Payload. The device can be implemented to protect against shock from any arbitrary direction. The name Shock-Limiting Interface, Compact (SLIC) is coined for this invention.

1. A limiting interface for supporting a payload relative to a structure, the limiting interface comprising:
 a frame assembly attachable to the structure; 
 a payload interface assembly for receiving the payload; 
 a suspension assembly disposed between the frame assembly and the payload interface assembly; and 
 an energy dissipating assembly disposed between the frame assembly and the payload interface assembly and adapted to dissipate energy transmitted to the structure, so as to limit a parameter of interest transmitted to the payload, wherein the energy dissipating assembly comprises a friction brake adapted to convert kinetic energy transmitted to the structure into thermal energy, the friction brake comprising:
 a brake material; 
 adjustable means for biasing the brake material against adjacent structure coupled to at least one of the frame assembly and the payload interface assembly to provide a braking force; and 
 means for limiting the braking force applied by the brake material against the adjacent structure; 
 
 wherein a force-displacement profile of the payload interface assembly is substantially a square wave. 
 
   
   
     2. The invention according to  claim 1 , wherein the parameter of interest is selected from the group consisting of displacement, velocity, accelerations jerk, vibration, force, energy, and shock. 
   
   
     3. The invention according to  claim 1 , wherein the suspension assembly permits relative movement between the payload interface assembly and the structure in a first direction only when acceleration transmitted to the payload is about to exceed a predetermined value. 
   
   
     4. The invention according to  claim 1 , wherein the suspension assembly permits relative movement between the payload interface assembly and the structure in a first direction only for as long as acceleration transmitted to the payload is about to exceed a predetermined value. 
   
   
     5. The invention according to  claim 1 , wherein the interface is adjustable, to accommodate payload mass. 
   
   
     6. The invention according to  claim 1 , wherein the energy dissipating assembly is capable of accommodating a plurality of events. 
   
   
     7. The invention according to  claim 6 , wherein after an event, the payload interface assembly is returned to a neutral position by the suspension assembly. 
   
   
     8. The invention according to  claim 1 , wherein the energy dissipating assembly is capable of accommodating a single event. 
   
   
     9. The invention according to  claim 1 , wherein the adjustable means for biasing the brake material comprises a pneumatic actuator. 
   
   
     10. The invention according to  claim 9 , wherein the pneumatic actuator is disposed at an angle relative to a direction of travel of the payload interface assembly. 
   
   
     11. The invention according to  claim 1 , wherein the payload is a person and the payload interface assembly comprises a seat. 
   
   
     12. The invention according to  claim 1 , wherein the structure comprises a vehicle. 
   
   
     13. A limiting interface for supporting a payload relative to a structure, the limiting interface comprising:
 a frame assembly attachable to the structure; 
 a payload interface assembly for receiving the payload; 
 a suspension assembly disposed between the frame assembly and the payload interface assembly; 
 an energy dissipating assembly disposed between the frame assembly and the payload interface assembly and adapted to dissipate energy transmitted to the structure, so as to limit a parameter of interest transmitted to the payload, wherein the energy dissipating assembly comprises a friction brake adapted to convert kinetic energy transmitted to the structure into thermal energy the friction brake comprising:
 a brake material; 
 adjustable means for biasing the brake material against adjacent structure coupled to at least one of the frame assembly and the payload interface assembly to provide a braking force; and 
 
 means for limiting the braking force applied by the brake material against the adjacent structure; and 
 an anticipating assembly disposed between the frame assembly and the payload interface assembly that repositions the payload interface assembly relative to the structure from a neutral position in anticipation of an event. 
 
   
   
     14. The invention according to  claim 13 , wherein a force-displacement profile of the payload interface assembly is substantially linear. 
   
   
     15. The invention according to  claim 13 , wherein a force-displacement profile of the payload interface assembly is substantially constant. 
   
   
     16. The invention according to  claim 13 , wherein a force-displacement profile of the payload interface assembly is substantially a square wave. 
   
   
     17. The invention according to  claim 13 , wherein the anticipating assembly increases a range of travel of the payload interface assembly relative to the structure in anticipation of an event. 
   
   
     18. A method for supporting a payload relative to a structure, the method comprising the steps of:
 providing a limiting interface attached to the structure and adapted to receive the payload; and 
 converting kinetic energy transmitted to the structure to substantially a square wave force-displacement profile transmitted to the payload using an energy dissipating assembly in the limiting interface comprising a friction brake adapted to convert the kinetic energy transmitted to the structure into thermal energy. 
 
   
   
     19. The method according to  claim 18 , wherein a magnitude of the square wave force-displacement profile is substantially constant. 
   
   
     20. The method according to  claim 18 , wherein a magnitude of the square wave force-displacement profile is less than a predetermined value.